For hygiene, paper towels beat air dryers, hands down

After using a public washroom, if there's both paper towels and an air dryer, which do you use?

If you answered 'air dryer', after the results of a recent study from the Queensland University of Technology, you may want to think again.

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In the long-standing debate on what's better to use to dry your hands after using a public washroom, both sides have fired off their salvoes at the other. There's the environmental concerns — towels are made by cutting down trees and washrooms go through a lot of them, but dryers use up electricity that may have been generated by methods that pollute the environment. There's the hygienic issues — many towel dispensers force you to use a handle to get the towels out, and touching the handle can spread germs back onto your freshly-washed hands, but dryers can have germs growing inside them, only to blow them onto your hands as they dry the water off. There's undoubtedly other reasons as well — aesthetic, convenience, and time to name a few.

There's even a website dedicated to the subject (although it seems a bit biased).

On the environmental front, it seems that air dryers come out as slightly better, and more cost effective, than paper. For hygiene, the results have been a little less certain. Some studies have shown no significant differences between the two, while others have said that air dryers can actually increase the amount of bacteria on your hands (compared to using a towel or not using anything at all), and some have shown that air dryers work just fine, and even better than paper, if you use them long enough.

It's that last point — about the time — that is apparently the most important, according to research done by Dr. Cunrui Huang.

"A hand dryer takes 30 seconds longer to achieve about the same dryness as a towel," said Huang, in a Queensland University statement. "This is important because most people spend less than 20 seconds drying their hands."

How many times have we started using the electric hand dryer only to get fed up that it was taking so long, and leave with damp hands?

It's that dampness that becomes the problem, because germs pass much easier via a wet hand than a dry hand. If you leave the bathroom with wet hands, you not only pick up more germs from things you touch, but you also transfer more germs from your hands to the objects. There are some air dryers that work much faster, like the Dyson Airblade, but whether they get your hands completely dry is still debatable.

Another factor noted by Dr. Huang was friction. Whereas the air dryers simply evaporate the water from your hands (in the case of hot-air blowers) or push it off (in the case of the Airblade), rubbing a towel over your hands to remove the water can actually wipe off many of the germs as well.

"Friction can dislodge microorganisms from the skin surface during both hand washing and drying," the report says. "Antimicrobial agents in soaps have too little contact time to have bactericidal effects during a single use or with sporadic washings, making friction the most important element in hand drying."

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So, at least for the most hygienic choice, you should probably go for the paper towels, and leave the air dryer alone. However, if you're not given a choice in the matter (which is frequently the case), and you're stuck using an air dryer, the key thing to remember is to make sure your hands are completely dry when you walk out that door, no matter how long it takes.

(Photo courtesy: Getty Images)

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